“Still another bugbear arises whenever common usage employs a word as a different part of speech from the one we are accustomed to. Above and following are now frequently used as nouns whereas they previously were adjectives, and there has been a great deal of hubbub about that development ... But such conversions are not unusual: In medicine we have prophylactics and sedatives, in military life we have privates, regulars and offensives, and more recently in broadcasting we have documentaries, visuals and specials. The list could go on and on. Nor would it be confined to the conversion of adjectives into nouns. It is just as common to find nouns doing duty as adjectives, beginning with such inconspicuous ones as rail road and stock yard and going on to population explosion and atom bomb agreement. The conversions are not always felicitous, but they cannot be forbidden as a class.”